The cross coupling of 2-bromo-1-phenyl indenes with phenyl acetylenes and other substituted acetylenes in water is a very useful process for making new chemical products that have indene and alkyne groups. Acetylenes, alkynes, and propargyl alcohols are important chemicals isolated from petroleum and other natural sources such as biomass and are used for different applications by the pharmaceutical, chemical, oil and gas industry. They are found naturally in oil deposits, in biomass in varying amounts, they are available from major chemical suppliers and inexpensive. Alkynes are reactive chemicals and storage can be problematic which is why they are usually not stored on site for deep sea oil and gas applications during production due to safety concerns from flammability, explosion and lack of space for safe storage of gaseous forms. Further, the reactivity that alkyne gases, liquids and solids have can make them challenging and sometimes difficult to store for extended periods of time due to decomposition. This high chemical reactivity and the different properties of alkynes make them valuable chemicals that are used by chemical and pharmaceutical industries. They have desirable properties that allow them to be used as cross linkers and plasticizers by the plastics industry and as chemical building blocks and intermediates to make medicaments for the pharmaceutical industry. The alkyne structure is found in several pharmaceutical medicaments and continues to be an important chemical that is used and further explored for the properties that they can provide.
Indenes are petroleum products found in the low boiling fractions of heavy oil, coal tar, and bitumen. They have many different applications for different industries. They are used as high energy fuels for marine and land applications, and are found as chemical components in resins, plastics, and performance chemicals. They are also used as valuable intermediates and building blocks for the pharmaceutical industry and have been used for the preparation of medicaments. Indenes are very inexpensive providing a very economical chemical feedstock to make other high value chemicals used by many industries. The availability and low cost of indenes makes them exceptional starting chemicals for different chemical processes.
The process of the present invention provides a way to couple alkynes and indenes. Currently, not a process exists that can couple a methyl or phenyl substituted indene with acetylenes. Methyl indenes do not have a high reactivity when compared to alkenes or aromatics and therefore a process that can couple indenes would be very beneficial. The process described uses available commodity chemicals to make higher value chemicals in water. In addition, additives are not needed which can lead to increased costs and environmental concerns. The process can also be catalytic and can reduce material costs, process costs and manufacturing costs.
Further, the process of the present invention is very versatile and can be performed in batch or in a micro flow reactor providing added advantages. Some processes are difficult to use in micro flow reactors because of compatibility problems associated with the chemicals used in the process. Micro flow reactors have many benefits from safety, control, speed of optimization of reactions and provide higher efficiency. These benefits provide the users of micro flow reactors additional advantages over batch methods due to increased control over these reaction parameters. This added control lowers waste generation and increases chemical yields.